CVE-2025-50343 is a heap-based buffer overflow vulnerability discovered in matio version 1.5.28, a library commonly used for reading and writing MATLAB MAT files. The vulnerability exists in the Mat_VarCreateStruct() function, which is responsible for creating MATLAB structure variables. The issue occurs when the nfields parameter, indicating the number of fields in the structure, does not correspond to the actual number of strings in the fields array. This mismatch leads to out-of-bounds memory reads and invalid frees during the cleanup phase, causing heap corruption or segmentation faults. Such memory corruption can be exploited by attackers to execute arbitrary code, crash applications, or cause denial of service. The vulnerability has a CVSS v3.1 base score of 9.8, reflecting its critical severity, with attack vector being network-based, no privileges required, and no user interaction needed. The flaw is categorized under CWE-122 (Heap-based Buffer Overflow). Although no public patches or exploits are currently available, the nature of the vulnerability suggests that exploitation could be straightforward in environments where untrusted MAT files are processed. This poses a significant risk to applications relying on matio for data processing, especially in scientific, engineering, and embedded system contexts.

For European organizations, this vulnerability poses a critical risk to confidentiality, integrity, and availability. Exploitation could allow attackers to execute arbitrary code remotely, potentially leading to full system compromise, data theft, or disruption of critical services. Scientific research institutions, universities, and companies in sectors such as automotive, aerospace, and industrial automation that utilize matio for MATLAB file handling are particularly vulnerable. The disruption could affect research data integrity and availability of computational resources. Additionally, embedded systems using matio in control or monitoring applications could suffer from denial of service or unauthorized control if exploited. The lack of authentication and user interaction requirements increases the attack surface, making automated exploitation feasible. The potential for widespread impact is heightened by matio's use in various open-source and commercial software stacks across Europe.

1. Immediately audit all systems and applications using matio 1.5.28 or earlier to identify exposure. 2. Apply patches or updates from the matio project as soon as they are released; monitor official repositories and security advisories closely. 3. Implement strict input validation to ensure that the nfields parameter matches the actual number of field strings before processing MAT files. 4. Employ memory protection techniques such as Address Space Layout Randomization (ASLR) and Data Execution Prevention (DEP) to mitigate exploitation impact. 5. Restrict network access to services processing MAT files to trusted sources only, reducing exposure to remote attacks. 6. Use sandboxing or containerization to isolate applications using matio, limiting potential damage from exploitation. 7. Monitor logs and system behavior for signs of exploitation attempts, such as crashes or unusual memory errors. 8. Educate developers and system administrators about safe handling of untrusted MAT files and secure coding practices related to memory management.